1. Field of the Invention
This invention relates to a roofing device for producing a waterproof seal between a waterproof roofing membrane and the curb surrounding a roof opening or a roof having a parapet wall. It also relates to roof hatchways employing such a roofing device.
2. Description of Related Art
Modern waterproof roofing membranes are extremely effective in providing a long lasting durable waterproof roof. To apply such a roofing membrane, rolls of the roofing membrane sheet material are unrolled to cover the surface of a roof to be sealed, and then cut to fit. Sealing of adjacent pieces of the membrane to each other with heat or adhesive form a perfectly waterproof cover for the roof. There are seldom problems encountered with such roofing membranes in the flat and unobstructed areas of the roof. However, when it is necessary to provide an opening in the roof, such as is required for a scuttle, access hatch, automatic fire vent or skylight, great care must be taken to ensure that the roofing membrane is tightly sealed to the curb wall surrounding the roof opening.
In the unobstructed areas of the roof, adjacent pieces of the roofing membrane are easily bonded together in flat, wrinkle-free seams. Because these portions of the roof are flat or only moderately inclined, the underlying roof fully supports the membrane and seams by the force of gravity that tends to hold the membrane in position.
However, at the curb surrounding a roof opening or along the parapet wall, the roofing membrane is turned around corners and up along the faces of the curb wall to maintain the waterproof seal. On these surfaces, there is no support for the roofing membrane and gravity constantly pulls on the roofing membrane, occasionally causing it to slip out of position, ultimately causing leaks. Thus, it is necessary to mechanically secure the turned-up edge of the roofing membrane near the top of the curb wall to provide support. This support is also important during installation of the roofing membrane when it is necessary to hold portions of the membrane temporarily in position before final sealing of the membrane seams.
Nailing the roofing membrane at the top of the curb is the present means of mechanical support. However, this punctures the membrane material and is often the source of leaks. Also, on the harsh exposed environment of the roof, conventional nails are prone to rusting. This requires specialized corrosion resistant fasteners supplied with the flashing accompanying a roof hatch. Unfortunately, the loose fasteners are difficult to distinguish from conventional fasteners, resulting in the substitution of non-corrosion resistant fasteners that corrode and fail.
The sealing systems in U.S. Pat. Nos. 4,941,300 and 5,263,287 disclose a sealing system with tabs that are integral with the wall flange to hold a longitudinal filler piece in a filler channel once the roofing membrane is wrapped over the filler piece. Unbending the tabs releases the filler piece from the filler channel to remove the membrane for repair, replacement, or accessing the roof underneath. The tabs permit installation of the roofing membrane without using separate fasteners that slow the operation. However, the prior art tabs do not allow for ease of removal, particularly where the curb or parapet wall is low in relation to the roof level. Also, the prior art tabs might puncture the roofing membrane if pushed in too far during installation.
Accordingly, one object of the present invention is to provide a waterproof sealing system between a roofing membrane and a curb that does not employ loose fasteners. Another object of the invention is to provide a roofing device wherein the spacing of the fasteners is even, providing good support for the membrane along the entire upper edge of its curb. Yet another object of the invention is to provide a roofing mechanism wherein the fasteners allow easy access to the roof beneath the roofing membrane, to repair, or replace the membrane. Still yet another object of the invention is to provide a roofing device which does not puncture the waterproof roofing membrane. A further object of the invention is to provide a reliable inexpensive and easily installed support for the roofing membrane at the upper edge of the curb. Still another object of the invention is to provide a pre-manufactured roofing mechanism of suitable size and shape to be positioned along the parapet wall of a roof or the perimeter of a roof opening. Still yet another object of the invention is to provide a roof hatchway, fire vent, or other roof mounted product integrated with a pre-manufactured roofing device, appropriate flashing and a curb suitable for positioning around a roof opening.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.